Just as the speed of computers and networks have increased dramatically over the past few years, so too have the number and variety of networked multimedia applications proliferated rapidly. Unfortunately, conventional Internet Protocol (IP) networks usually only offer a so-called best effort (BE) service to communicating devices. This BE service does not make any service quality commitments. However, most multimedia applications are delay/loss sensitive. As such, these multimedia applications/devices would benefit from what is commonly known as Quality of Service (QoS) support/guarantees from the interconnecting network(s).
Consequently, the current Internet is becoming increasingly inadequate to support the service demand from such multimedia applications/devices, such as, for example, multimedia streaming applications/devices.
To support QoS in the Internet, the governing Internet Engineering Task Force (IETF), which is the main standards organization for the Internet, has defined two architectures that are expected to be implemented in the future, namely an Integrated Services or Intserv, and a Differentiated Services or DiffServ.
The integrated services model basically provides per-flow QoS guarantees. Here, a Resource Reservation Protocol (RSVP) was suggested for resource admission control and resource allocation. However, it is very complicated for conventional backbone routers in the network(s) to maintain the current states of thousands or more communication flows (e.g., streaming media packets).
On the other hand, the differentiated services model gives a class-based solution to support a relative QoS. Essentially, in differentiated services, packets can be divided into different QoS classes and forwarded at different priorities. The QoS class of each packet is specified in IPv4 by the Type of Service (TOS) byte or in IPv6 by a Traffic Class (TC) byte. Being highly scalable and relatively simple, the differentiated services model may come to dominate the backbone of the next generation(s) of the Internet.
Scalable coding (e.g., temporary, special and/or quality scalability) for different kinds of media has become one of the more important trends as of recent in the multimedia compression area, both in industry and academia. Many scalable coding methods have been suggested, such as, for example, layered coding, fine granularity scalability, embedded coding, and wavelet coding, to name a few. Scalable coding methods are very useful for multimedia transmission due to the network bandwidth fluctuation.
As the technology of the Internet and other like networks continues to grow there is a need for improved methods and arrangements that can effectively take advantage of the planned services and/or other coding schemes to provide an improved multimedia communication environment.